1. Field of the Invention
This invention relates to an image-drawing processing apparatus and an image-drawing processing method, and particularly to an apparatus for and a method of performing image-drawing processing on image-drawn objects or image-drawn objects such as characters or graphics with the image-drawn objects as an input.
2. Description of the Related Art
Upon printing a paper document by a page printer, PDL (Page Description Language) such as Inter press (Registered trademark of U.S. Xerox Inc.) or PostScript (Trademark of US Adobe Systems Inc.)are commonly used as an input printing image.
When such a PDL is printed as the input, an imaging process for converting data represented in a PDL format to data of a format fit to a raster output device must be performed. However, the time required to execute the imaging processing is commonly very long and hence this turns into a problem for a system or the like for outputting data to a high-speed page printer in particular.
Even though, for example, a color high-speed page printer has an output capacity of above 40 sheets per minute, the time required to perform imaging processing needs several tens of seconds to a few minutes and hence the capability of the expensive high-speed page printer could not be utilized sufficiently. Thus, the speeding up of the imaging processing needs to perform parallel image-dawning processing.
Japanese Published Unexamined Patent Application No. Heisei 4-170686 discloses, as a technique for executing the parallel image-drawing processing, one for dividing an image-drawing area into rectangular form and performing parallel processing on filling areas or regions lying within the divided respective areas.
According to Japanese Published Unexamined Patent Application No. Heisei 6-28126, an image-drawing area is divided into band form and the divided areas are subjected to parallel image-drawing processing by a plurality of computers or a plurality of printer devices.
However, the prior arts described above needed to re-arrange data on image-drawn objects every areas in advance before the image-drawing of the divided respective areas in parallel. Namely, these arts needed to carry out, prior to image-drawing processing, a process for making a preparation so as to check to which divided areas the respective image-drawn objects belong, e.g., copy and divide data when they belong to the plurality of areas, and perform the image-drawing processing on the objects independently every divided areas.
Particularly when the area is divided into pieces and loads every areas are predicted to thereby keep in balance loads applied to a device for performing parallel processing, the time necessary for the pre-treatment increases.
Namely, when the area is divided into pieces, the probability that division processing will be effected on each image-drawn objects, is increased, so that its processing time takes long.
On the other hand, when each area is not uniform in size or form, a process for checking to which divided areas the individual image-drawn objects belong, will turn into a search problem heavier in processing load, which is other than a simple arithmetic operation.
Therefore, the prior arts could not obtain a sufficient paralleled effect due to both overhead of the pre-treatment itself and a loss produced due to inability to keep the processing loads in balance in order to prevent the pre-treatment load from being excessively increased.
In contrast to this, a method is also considered wherein image-drawing processors to which areas are assigned, respectively read all of image-drawn objects data without preparing image-drawn objects data every divided areas in advance and respectively adopt or reject them.
This method brings about an increase in the amount of transfer of data and needs to make a check as to whether the respective image-drawing processors require the data about all data. Therefore, the overhead increases and eventually the parallel processing effect could not be obtained well.